
Finally getting back to working on the old browscap module, and needed to ape a particular browser string. I found this article on configuring Safari and Firefox to accomplish this:
Spoofing the User Agent with Safari or Firefox
So, first I do the command using Safari's actual browser string, so I can easily revert to it later:
defaults write com.apple.Safari CustomUserAgent "\"Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_5_2; en-us) AppleWebKit/525.18 (KHTML, like Gecko) Version/3.1.1 Safari/525.18\""